Depending on the processed material from each drill must be properly sharpened. To verify the correct angle will help a specially prepared square plate of copper or aluminium with a thickness of 1 mm.
To become operational protractor enough to cut it cut, as shown in the picture: a large cutout at an angle of 120 degrees, the other half is 60 degrees and the surviving corner of a square is 90.
Recommend to read
ELECTRONIC EAR
Check slabovidimym acoustic signals is of great practical importance. This: fault diagnosis of internal combustion engines; search for places of leakage of gas from the damaged pipeline...
INSEPARABLE COUPLE
Mini tractor trolley. The design of the mini-truck went, as usual, the units of various automobiles and agricultural machines, end time. I was able to fairly compactly place them in a...